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SCIENCE
Whether it’s carrots to see in the dark or stories about WWII fighter pilots eating blueberry jam
to make their sight keener, dietary advice on improving eyesight is plentiful. However,
what foods and nutrients could actually have an impact on eye health? Raconteur investigates the science behind the myths
to understand what’s at play
Gamma-linolenic acid (GLA) is an omega-6 fatty acid, which unlike other omega-6 fatty acids has anti-inflammatory properties. Studies have shown that the fatty acid can have a positive impact on meibomiam gland dysfunction, a primary cause of dry eye.
GLA is not a widely occurring chemical compound but is available in a selection of plant oils.
Lutein and zeaxanthin are two carotenoids - the pigment responsible for the orange colour in certain vegetables and fruits - that play an important antioxidant role in the eye. They work by defending the macula region of the retina against unstable molecules called free radicals. Specifically, they cancel out harmful oxygen free radicals and help block blue light damage.
Lutein and zeaxanthin are commonly found in leafy greens, but also in pistachios, egg yolks and red grapes.
Omega-3 is a polyunsaturated fatty acid, which contains EPA and DHA, both of which are vital for proper visual development and retinal function. As a result, a deficiency is linked to impaired vision and retinal degradation, particularly in children.
EPA and DHA are concentrated in oily fish but vegetarian DHA can be manufactured from microalgae.
Vitamin A is a group of unsaturated fat compounds that are vital to human health. Consuming food rich in the vitamin can help combat night blindness by helping maintain rhodopsin, a light sensitive pigment found in the retina. Furthermore, it has been shown to slow the deterioration seen in age-related macular degeneration (AMD), the leading cause of blindness in the developed world.
The vitamin is most prevalently found in its active form in animal products. However, it also exists as a provitamin A carotenoid in some fruits and vegetables, which the human body can convert into its active form.
Gamma- linolenic acid
Lutein and zeaxanthin
Omega-3 fatty acids
Vitamin A
Vitamin E
Conditions helped Conjunctival xerosis (dry eye) Diabetic retinopathy Glaucoma High eye pressure Neovascular macular degeneration
Conditions helped Conjunctival xerosis (dry eye)
Conditions helped AMD Cataracts Diabetic retinopathy Eye detachment Uveitis
Conditions helped AMD Conjunctival xerosis (dry eye) Bitot’s spots Corneal scarring Corneal ulcers Corneal xerosis Night blindness
Top five sourcesmgs per serving
Beef liver 6.4Lamb liver 2.1Liver sausage 1.5Cod liver oil 1.4King mackerel 0.4
In addition to being critical to tissue repair and immune system function, vitamin C is also a powerful antioxidant, which is needed by the human eye. Indeed, studies have shown that the vitamin is linked to decreased risk of cataracts and AMD
As an essential vitamin, vitamin C can’t be produced by the body, meaning that it has to be obtained from fruits and vegetables.
Vitamin CVitamin E is a group of fat-soluble antioxidants that can help protect the fatty acids in the retina. Research suggests that vitamin E is linked to the reduction in cataract formation, and in severe cases a deficiency may lead to retinal degeneration and blindness.
The vitamin is common in most foods but especially rich in cooking oils, seeds and nuts.
Conditions helped AMD Cataracts
Kakadu plumsAcerola cherriesGuava Rose hips Chili peppers
2,65082212611965
Top five sourcesmgs per serving
Conditions helped Cataracts
Wheat germ oilSunflower seedsAlmond Hazelnut oilMamey sapote
2010
7.36.45.9
Top five sourcesmgs per serving
Oysters BeefAlaskan crabFortified breakfast cerealLobster
747
6.53.83.4
Top five sourcesmgs per serving
Zinc is a part of many essential enzymes, including superoxide dismutase, which works as an antioxidant. Research suggests that is involved in the formation of visual pigments in the retina and consequently a deficiency can lead to conditions including night blindness and cataracts.
Zinc
Conditions helped AMD Cataracts
Top five sourcesmgs per serving
Mackerel 4,107Salmon 4,023Herring 3,181Cod liver oil 2,664Oysters 565
Top three sourcesmgs per serving
Borage oil 210Evening Primrose oil 76Blackcurrant oil 70
Top five sourcesmgs per serving
Kale 23.7Salmon 20.4Herring 19.3Cod liver oil 14.6Oysters 12.2
